SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd51ce87e12d79042ad97c755e08bf45b24408a1c77ab75bb98e89c0e7a39ac92' 
  AND token = 'rIEAHLw8xJhCVMHjQrNhkK+Ir2K8WDhSnclLsUgqHw0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}